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Both calculators run independently — change the inputs on either side to compare results.

HVAC BTU Room Sizing Calculator

Size an air conditioner or mini-split to a room. Enter the room length and width, the ceiling height, choose the room's sun exposure, and add the number of regular occupants to estimate the cooling capacity in BTU per hour you need.

Room Length (ft)

Room Width (ft)

Ceiling Height (ft)

Sun Exposure

Regular Occupants (people)

Fill in the required fields to see your result.

Construction

Multi-Room Paint Calculator

Estimate the gallons of paint needed for a whole project across several rooms. Enter the number of rooms, average paintable wall area, the percentage taken up by doors and windows, how many coats you plan, and your paint's coverage to get a precise gallon count.

Number of Rooms (rooms)

Avg Wall Area per Room (ft²)

Doors & Windows (%)

Number of Coats (coats)

Paint Coverage

Fill in the required fields to see your result.

Key differences

	HVAC BTU Room Sizing Calculator	Multi-Room Paint Calculator
Category	Construction	Construction
Inputs required	5	5
Result	Cooling Capacity Needed (BTU/hr)	Gallons of Paint Needed (gallons)
What it does	Size an air conditioner or mini-split to a room. Enter the room length and width, the ceiling height, choose the room's sun exposure, and add the number of regular occupants to estimate the cooling capacity in BTU per hour you need.	Estimate the gallons of paint needed for a whole project across several rooms. Enter the number of rooms, average paintable wall area, the percentage taken up by doors and windows, how many coats you plan, and your paint's coverage to get a precise gallon count.